The only thing I can think of is using a custom report, in the report you can then have 1 asset in multiple groups.
Basically, you would create a custom column in the report (with a case statement) which looks at the other IP addresses an asset has and shows a value based on that.
Problem with doing that is that secondary IPs are not stored numerically, so it is hard to create a condition that checks for a range. In fact you would have to convert the IP address to a numeric value and then do the condition check.
Do note that this is not real grouping, it's just grouping in the report itself, but nowhere else in Lansweeper.
