Question: I am trying to make a simple map with the following legend:
[![enter image description here](https://i.stack.imgur.com/aQmID.png)](https://i.stack.imgur.com/aQmID.png)

Whatever I change in the settings I can't get the other boxes of the predicted deprivation section to be place under the group title. Ideally I would like to have 4 columns UNDER the group title with 2-2-2-1 boxes. Any ideas?

Answer: 
It's not clean but a trick is to create a legend per column.
Then you edit each column by deleting / hiding the objects you are not interested in.

This solution can help you on a one-off basis.
I don't think this is possible within QGIS. So I suggest you export your map to Inkscape and edit it manually.

Once you're done with all other things you want in the print composer , export your map as SVG then open the SVG with Inkscape.

Inkscape is a free and open-source graphic design software. So it blends seamlessly with QGIS.

You can download and learn more about Inkscape here:
<https://inkscape.org/release/inkscape-1.0.1/>

If you're absolutely new to Inkscape, this tutorial can get you up and running in a few hours: <https://www.youtube.com/playlist?list=PL__WA5iiRT53V2UobbmFvzAW_-LJMkPIV>