Not really, but…
Select the layers you want to merge in the Design Director.
Right-click and choose "Select By".
All objects in the selected layers will be selected/highlighted.
Click in the "Active" column of the layer you want these objects placed. It can be any layer; selected or not.
All the selected objects should be merged onto the layer you chose.
The unused layers will remain to be reused elsewhere or you can select them and Delete them via the palette Local Menu or "Ctrl+D".
V17—V21, 2015, 2016, 2017
Designer, Deluxe, Expert, Basic, Platinum
Windows 10, 64-bit