As long as you can access a site with ssh account, then you can transfer files using scp, try to imagine , you are from host A and you have access to host B through ssh with same user account call foobar. You can copy a file from host B by example as bellow
scp foobar@hostB:~/myfile.txt .
:~/ actually leads you to home directory of foobar, as long as the file is accessible by the account foobar in host B, than it can be transfer. The other way round is transfer file from host A to host B.
scp myfile.txt foobar@hostB:~/
It support to copy a folder from one host to another by adding option -r
scp -r foobar@hostB:~/myfolder .
Copy from one host to another with different ssh account.
scp foobar@hostB:~/myfile.txt root@hostF:~/