How will the title field be parsed into keywords. Do you want each set of words delimitted by commas to be a "keyword"? Or do you want each individual word to be a keyword?
With either option, you can use the substitute function to parse the title into keywords. Then you can define a value list to reduce the list of keywords to just unique instances of each. ValueListItems is a function that can then copy the value list into the global field. (And the valuelist can be made a conditional value list to return unique values just for the current record if you want.)
With a return separated list of keywords in an indexed field in your records and a return separated list of values in your global field, you can use this pair of fields as match fields in a relationship. Then the relationship will match to any records where any one value in the global field matches to any one value in the other list.
If you want to use commas as delimitters:
Substitute ( TitleField ; "," ; ¶ )
If you want to filter out punctutation and use spaces as delimitters:
Substitute ( Filter ( TitleField ; "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz'" ) ; " " ; ¶ )