This is sort of a verbal description of what Andrew's animation
Just use a couple of plywood panels or thinner dimension frames
with thin ply panels/veneers and a couple of long piano hinges,
or some other more robust hinge. I advocate using piano hinges
to help impart extra strength and rigidity as the hinges for this
style of folding door take a lot of stress in their dual function of
support and movement. Piano hinges are simple and straight-
forward. Their benefits outweigh any additional cost I think.
On the "MAIN" bath door - the one you see as the 'bath entrance door'
from the inside of the camper -, use the first piano hinge to
attach it so that it opens into the inside of the camper in the
direction you want it to. On the INSIDE of that MAIN bath door
[the "outside" door of the two when looking from the PP/toilet
position], on the opposite side that the MAIN bath door's piano hinge
is on, install the second panel/door with the other piano hinge.
[You could also install a third panel if you want "total" enclosure,
but would be extra material and additional weight for the animation's
design - it just depends on your design and needs.] Just remember
to install the MAIN bath door piano hinge in a manor so that that
door can swing out to flat against the plane of the interior cabinets
face or seat(s) inline with the MAIN door when it is normally closed -
or in other words, 180degrees of movement for the MAIN door outwards.
[This allows you be able to 'get around' the door from the interior and
position yourself in front of the PP/Toilet so that you can pull the
enclosure into position with you inside of it.] The inner door needs
it's hinge mounted so that it can swing out to 90 degrees from the
MAIN bath door, so that when you pull back the MAIN bath door with
the Inner door at the 90 degree open position, that it's unhinged
end will rest against the end wall to complete the enclosure as per
I would avoid the vinyl accordion doors myself, based on personal
experience. They're not long lived enough for their cost and they can
stink - especially the cheaper ones. Just my opinion on them.
If you have a house - you have a hobby.