Upload media images via odk central that are not part of xlsform choice list/survey directly

1. What is the issue? Please be detailed.
I have designed a xlsform where I display image for note based on the previous selection.
So the I upload media file through central, I can't see the list of those images. as they are loaded through dynamic variable.
how can i push the those images in media folder of form

2. What steps can we take to reproduce this issue?

3. What have you tried to fix the issue?
If i use google drive and upload form, I can simply copy the files in media folder and it works.

4. Upload any test forms or screenshots below.