The lists below are extracted from the top 100 world rankings published by FINA, filtered to show only Commonwealth swimmers, generally limited to 3 per nation as entries are at the Commonwealth Games themselves, with one notable exception. At FINA level, of course, no distinction is drawn between the home nations of England, Wales and Scotland so in an effort to recognise this while minimising the processing overhead, the lists include the top 9 GB swimmers. Inevitably this means that some swimmers in the top 3 from each of the home nations will be omitted, but those at the sharp end of Commonwealth competition should be captured.
The second point to note is that these rankings make no attempt to filter swimmers by whether they have been selected for the Commonwealth Games by their nation or what events they may swim, although it's likely that those at the top of each event can be expected to be competing on the Gold Coast. The rankings shown are world rankings for context.