Yes you can, I've done it a while ago, there's a feature in multiman that allows you to stream games from a PC or a PS3, you can also use this feature to transfer files.
The problem with is that it doesn't transfer games in the "Folder" or JB format , Multiman just crashes instantly, you can however transfer games that are already extracted in the "game" folder, i.e: games that are extracted from the pkg file. It also works with iso if I'm not mistaken.
I've tried transferring a video that was 200kb in size, and it worked fine but I didn't test it with more than that
My memory is a bit rusty so bear with me:
1-Set up a manual connection between the two devices using an ethernet(use the same Subnet Mask, Default Router, and DNSs in both systems, but different IPs, if you don't already know that)
2- Open multiman and go to settings Remote Access Permissions and set it to "Full" (I've done this in both systems because idk, although in theory you should just do it for the system you want to access)
3- In the system you want files to be transferred to, open multiman and go to Settings, and then Network Servers and choose Nethost-Enable, enter the IP address, leave the Port number unchanged. and enter my nickname as the server's name.
4- Use Multiman's file manager and you should see it there.
5- After you transfer your files, Rebuild Database