A dent or contour depression in the buttock/hip area can sometimes be improved, but the best plan depends on what is causing it. In the photo, there appears to be a visible contour indentation along the buttock/hip area, but an exam is needed to judge whether this is mainly a fat deficit, skin tethering, scar tissue, or natural anatomy. If there is enough donor fat, a staged fat transfer can sometimes soften the depression and improve the transition between the waist, hip, and buttock. If the dent is tethered by scar tissue or tight bands, the surgeon may need to release that area before or during fat grafting; simply adding fat over a tethered area may not fully correct it. If there is very limited donor fat, poor skin quality, or a deep structural hollow, the improvement may be partial rather than complete. I would ask for an in-person evaluation with a board-certified plastic surgeon who performs revision BBL and body contouring. They should assess your donor fat, skin elasticity, scar tissue, and whether a staged approach would be safer and more predictable than trying to overfill the area in one surgery.