I need to sort a multi-thousand records table and here is an extract;

Seq
1
1.1
1.111
2
1.1.2
1.1.2.1

so it will end

Seq
1
1.1
1.1.2
1.1.2.1
1.111
2

It can be up to 7 levels. What would be the best strategy? I would be fine to add 7 columns as sublevels, I just don't know how to populate them.

TIA.