Source Control Workflow

First of all sorry if this isn’t in the correct section.

If there is anyone that has experience with source control i would be very grateful if you would share.
I need to get some of my colleagues to work with me simultaneously on a level. I’ve managed to get source control working with svn.
But we can’t seem to find the workflow that works.Yes we are connected, but it seems that it’s either him or me that can work, and not both.
Now, before you ask, yes i have read the documentation, and yes i didn’t understand a thing ).I worked with similar solutions, but this one baffles me.

We get conflict after conflict and all of the time, one of us looses his work.We are doing archviz.
How can i get my colleagues to work on different areas ?
I understand that we can’t edit the same thing at the same time, and that the is a locking system where you can lock/reserve a mesh / material / blueprint etc.But it seems that if one of us sends a change, the level map looses the unsent changes.

Let’s try please to make this workflow to be clearer and dumb it down )
Say there are 3 computers A, B and C

  1. A imports the basic volumes of the level
  2. they all are connected with source control - basic volumes, walls and all that
  3. A wants to do the bedrooms, while B does the kitchen, and C does the lighting

How would they(we) proceed ?
edid: - 2 other question :

  1. is it possible to reference objects from 2 different levels? aside from content browser? like a proxi … thinking out loud, might be a great blunder )
  2. how do the big game studios do it? if you have say a huge castle, do they have just 1 guy slave away on that level ?

Thank you immensely for any help with this

Sub levels!

There is still a problem with potential conflicts arising from when one of your devs builds the level (as all levels are touched when you do that), but basically give all of your devs their own level to work on, then stream those levels into your main level file (the persistent level).

Look into Blueprint Communication for answers on how to talk between levels and sub levels.