How do I grow my booty back?

I used to be very thick (hips ,booty etc ) having 3 babies boosted that even more but in the last year I’ve lost a lot /most of my baby weight which is nice but to be honest I loved my thickness , don’t get me wrong I still have some curves and booty but I’m definitely loosing some of everything even my breasts are shrinking. I guess I’m wanting to know who else this is happening to or happened to i live that I lost some of my stomach but I want to regrow my butt,hips etc . Any advise or foods to eat , exercises to do , etc I’ll take it all .