Yes! Yes you can!
It should be fine especially if the roots are able to grow through the 3 gal fabric pot
And if you don’t care about reusing the 3 gal pot you can cut the bottom off before putting it in the 5gal
I’m assuming the roots don’t want to budge from the smaller pot? They should be okay even if they get somewhat damaged when transplanting
Maybe check out this BOG Double Pot technique
He uses plastic pots but there’s also a pick of a grow bag being placed directly onto soil, which is basically what you’re doing