How do get Db dim?

Hi… just building a prgression… F, Ddim and want to go to… Dbdim, but can not work out how!? Can anyone help please?

What key are you in?

F Just doing a simple progression

F, D dim, Db dim, Dm, F

Hi and many thanks for your time!

I did try these, but don’t really understand how they work!?

But… you solved my problem, so thanks again!

If in key of Fmajor, ddim is borrowed from dorian mode (f dorian 6 is a vi rather than f minor’s VI). it has to be borrowed.

c#dim is a non diatonic chord when working in the context of Fmajor. it needs to be pulled from non-diatonic box on right.