Here is a funky little fidget spinner in the shape of a Trinity Knot. This requires a 608 bearing and a pause at layer 43 at which point you add the bearing - tolerances are very tight to avoid needing glue so you really need to push it in firmly until it sits flush (it will actually sit just below the current layer so there is no chance of collision when printing continues).

The buttons then push fit after printing is complete, depending on filament/print settings you might want a drop of glue to join the two, but standard settings on PLA Silk mine have just press fitted and not come apart.

The objects need separate settings, with the buttons having standard, automatic supports and the spinner having supports disabled (unticked)