This is kind of a tricky question, since 'Broly God' is from that weird 4-D Show at Universal Studios Japan.
Legendary Super Saiyan (which I'll use to refer to Broly DBZ's form and Kale's form) is shown to be inconsistent in terms of power between Broly and Kale. Although Broly DBZ took a pretty big beating in the first two movies of Broly trilogy, the power it took for him to be defeated is clearly less than the power it took to knock out Kale during the Tournament of Power. Broly DBS's Full-Power Super Saiyan (Not technically LSSJ, but instead Ikari/Wrathful stacked on top of Full-Power Super Saiyan) is shown to only be able to be beaten by Gogeta Blue, a Metamoran Fusion. Broly God is also beaten by a Metamoran Fusion (though, the power that a crowd of humans at a 4-D live event would add to an SSJB Metamoran Fusion would probably be a lot less than SSJB Gogeta, but for the sake of argument let's say God Fusion Goku is as strong as SSJB Gogeta).
From all this, I'd say that LSSJG = Broly DBS's FPSSJ. However, if Kale were to somehow take on the Broly God form, it might be Kale's LSSJG > Broly DBS'S FPSSJ.
Broly God one shotted SSB Vegeta, and completely dominated SSB Goku who I believe never landed a single hit. They needed stupid plot bs like fusion with an entire crowd to beat Him and even then he managed to fight back for a good time before the blast struggle where he ended up dying from SSB crowd Fused Goku. I think Broly God has the edge, albeit not by much.
Shouldn't be, but apparently it is. As Broly God without a single scratch nor being touched took down SSB Goku and SSB Vegeta. It was plot fan involved BS. So we can only scale it by how he fought Goku and Vegetas as SSB's, he took no damage and didn't get touched, yet he put Vegeta out with one attack and whooped Goku's ass easily.
The movie appears to follow the manga storyline as that is what Toriyama mainly deals with which is why he skipped over it since the movie was made. It’s possible goku and Vegeta are using the Evolved Perfected SSB but that’s an entirely different can of worms.
Broly:BR tanked a combined blast from and destroyed SSB Goku and Vegeta whom have gone through the ToP, this was not even close to his full power, Broly:BR wins.
they used a god fusion to beat broly god(as in slightly different ,possibly stronger version of fusion dance not sure really) while the new broly best feat was overpowering two super saiyan blues(jiren did that twice as better)