Glute gains but slim thighs

Building glutes will come from proper training and providing the calories necessary to grow muscle, so either eating in a surplus or at least at maintenance. If you still have weight to lose muscle growth is possible but usually not very significant, but you can help retain the muscle you have to shape it. Your thigh size will depend on how you lose fat and how much muscle you have. If you want to avoid building or retaining the muscle there (or at least excessively) don't focus too much on progressive squats or other quad dominant movements like leg press. More glute bridges, hip thrusts, deadlifts, abductions etc.

This article might help too

https://bretcontreras.com/growing-glutes-without-growing-the-legs/