This blog will explain why the gods, such as SSJG Goku and above have multi-Universal destructive potency and range.
1. The infamous Goku and Beerus battle at the beginning of DBS.
Goku and Beerus can destroy the Universe, and even the entire Macrocosm.
We have statements of Goku and Beerus exchanging Universal erasing blows. Which actually extend into other dimensions such as other world which is as big as the universe as well.
http://static3.comicvine.com/uploads/original/14/142960/5193678-5826660289-BPb02.jpg
http://i.imgur.com/cOY7hJA.png
http://static1.comicvine.com/uploads/original/11127/111271675/5470848-9426412013-At1Tr.jpg
As seen here it was even reaching to other world and kai realm.
Here is a map of the DB U7 macrocosm, see how the other world is as big as or bigger than the mortal universe (also note every Universe has one of these)
As you can see destroying even U7 macrocosm like beerus and Goku can is multi Universal in scale.
Now some people argued that they could not destroy space and time, thus this is only limited to 3D matter but that is not the case. Not only is it stated they would destroy the Universe itself, not just the matter, and not only did it permeate space and time to reach multiple space time continuums like other world and the living Universe, but later on in the series we actually got undeniable proof of spatial and temporal destructive power and control.
2. Vegeta destroys ROSAT space time continuum from within.
During his training to battle Zamasu and Goku Black Vegeta destroy's ROSAT from inside to return to the living Universe. This is proof of destroying a 4D space time continuum.
https://www.youtube.com/watch?v=W4OTiXRRB1k
The time chamber has it's own flow of time and space, buu and gotenks literally had to rip a hole in space time to escape as there is no exit in it aside from the doorway. That’s why it gives them different timeframes in it to train, since it’s a separate time space. It is also even stated by Dende that the time chamber is an alternate Universe directly.
Some people will argue that ROSAT is the size of Earth because Goku stated he thought it is supposed to be the size of Earth, however it clearly is stated to have no exit multiple times, as in not finite, and it also is directly stated by Dende to be a Universe, even in DBS Goku mentions Whis realm is like ROSAT and has no exit. Also it is a large 4D space time continuum regardless of its 3D size anyway.
https://jctunesmusic.files.wordpress.com/2015/12/screenshot_2.png?w=474
Therefore Vegeta destroys a parallel Universe and this alone proves that the gods in DBS have the ability to destroy space time even while in base at this point.
3. Zamasu controls the timelines.
After becoming one with the Universe at the end of his arc, Zamasu continues to fuse with the entire timeline that Zeno had to destroy in order to defeat him. This timeline includes 12 Universes, which each include a macrocosm, which I went over earlier.
Then we see that Zamasu was even beginning to effect the present timeline to, so he was spreading even further past the future timeline and it's 12 Universes, and effecting even other sets of Universes.
This clearly makes Zamasu and Zeno At least Multi Universal to be able to fuse with and destroy multiple sets of Universes and space time continuums. The question is who does this scale to. Well we know for one thing Beerus is still considered to be more powerful than Goku Black and the other characters during the Future Trunks arc according to the producer himself.
"The God of Destruction Beerus is overwhelmingly strong, but if we leave him out, then I think the strongest fighter is Goku Black. I’d say he’s used Son Goku’s power as a base and evolved in his own, unique way."
Notice how the producer even mentions fusion Zamasu specifically as well. The fact Black is technically still Fusion Zamasu, yet he thinks Beerus is still superior to who he calls the strongest so far proves that he is including every form of Black/Zamasu. There is no doubt that Beerus is superior to this form of Zamasu, in fact he and Whis don’t even feel the need to intervene during the battle as a testament to the fact it is not a threat to them. So therefore Zamasu/Blacks feats would easily scale to Beerus and up as well.
Now as for if they scale to Goku, this one is a closer call, however there is more than enough evidence to suggest they do at least somewhat. First off Goku, Vegeta and Trunks were able to temporarily reflect one of Fusion Zamasu's energy blasts, and protect the time machine and bulma, kais etc from it. They also take hits from this new form of Zamasu.
https://youtu.be/KYUKujL2BLQ?t=111
Goku even believes if he had more senzu beans he could fight Zamasu.
https://youtu.be/KYUKujL2BLQ?t=255
So in conclusion, while Goku is weaker than Zamasu/black in this fused form, he can take hits from him in this form, and counter Zamasu's attacks to some degree, thus he should logically scale to him as well. This also fits with the previously shown feats.
4. Goku destroys Hit's space time.
Goku in a recent episode of DBS was shown to destroy Hit's space, which he created with the skipped time of the actual timeline. It is confirmed that this is a separate space and time directly. This again shows Goku destroying a space time structure, not just matter, with his power.
https://youtu.be/0UfdnmL2Bw4?t=54
http://i.imgur.com/k1XAD8q.jpg
http://i.imgur.com/X5dSSI7.jpg
So in the end we can conclude that indeed the DBS gods have proven to be able to destroy not just the Universe, but the macrocosm itself, and even multiple macrocosms as seen with Zamasu and Zeno. Also we have concluded that they have multiple undeniable feats that prove they can destroy not just matter but entire space time continuums as well. Thus this is why they are undeniably to any reasonable person Multi-Universal minimum.