Bleeds for an Sqaure Cross Fold document - How to?

Wherever it goes over the trim line is where the image needs to extend beyond the line.

Are you looking to add bleed line in InDesign? You won't be able to do this. 

Once it goes over the line it will be trimmed off at finishing.

You're better off having each image separate. For example if that's a large image spanning the 3 panels - copy and paste it 3 times in to the same place (edit>Paste in place)

Then resize each to the correct panel size - then extend the image past the line.

If the image doesn't have bleed - then you'll need to increase the image size and make some adjustments

or edit the image to make it work.

Alternatively - you could plan it out as you have it as a guide for the printers. 

Then setup an InDesign document with individual pages at the correct size for each panel. 

Then give the printers a multipage pdf along with the planned page for each panel.

The printers will impose the document correctly for the required printing method. 

Confirm please.

The red holding line represents the final trim? (The piece will need to be die cut and that line will be used for the die. Reduce its stroke weight.)

I don't understand the final square panel orientation(s) from a user/recipient view but you need to bleed the two photos and red tint fill.

The "head" needs to fill a frame extending down an right +5mm.

The other photo could be duplicated in place over the existing and its frame extended up, left and down 5mm than cropped at the center fold to align with the center panel.