3D view : https://a360.co/2Bs5G1S

just print the 2 parts with the "poles" up (should take 3h with 0,2mm layer height)

and you will need ~80cm of PTFE tube (the one for 1,75mm filament, so ~4mm outside diameter) and cut it in 4 sections of 20cm to slide them in the grooves of the pieces

then assemble the 2 pieces together through their "poles", and you should be able to scoop under the stored spools, make sure the holder is stable on the wood, then pass the filament end through the hole in the female part to guide it

if everything work according to plan, swapping spool should be a one hand operation taking around 10sec :p