This tree-shaped decoration is part of a set of three that features different mathematical Triply Periodic Minimal Surfaces. The bottom can be left open for use as an electric tealight cover or decoration, or you can use the threaded insert to hold objects inside.

See here for video: https://youtu.be/5yMM924_57E

See here for others in the series: Gyroid: https://social.thangs.com/m/503650 Diamond: https://social.thangs.com/m/503651 Fischer Koch S: https://social.thangs.com/m/503653