Hi @Nickb and welcome to the community!
As @elsamuel mentioned, it is quite difficult to help with such little information, but I’ll try anyway 
This sounds like a challenging task!
I would split your task into two subtasks: getting all the tags in the strings, then search for the combinations.
Getting the tags:
Inspired by @ScottF’s post, I’d build a workflow like such to get all tags in a sentence:
Given a List of Tags, it will build rules with the “string manipulation” node out of these, then use the “cross joiner” to get all possible tag-string combinations and apply those rules with the “rule engine (dictionary)”. The final result can be aggregated with the group by node, by grouping on the “strings” column.
Getting the combinations:
To take it from there, I think this is a question of how to represent combinations. I would opt to put them in lists, for example with the “GroupBy” Node. This allows then to use the “Subset Matcher” to getthe final result
Here is the whole workflow:
I hope you can take it from there! Let me know if that helped
Best, Lukas