Is there a scalable function in Excel that does the same as nesting IF(ISNUMBER(SEARCH) functions?

I am trying to find a better way to search for specific strings in each cell of a column of categories, and then classify those categories together based on which strings are found inside them.

The column 'Advertisement' contains the different categories and the column 'Trees + Cars' is the result column which extracts 'Trees', 'Cars' and classifies categories missing those strings as 'Other'.

If this were a case of looking for one string only, I could use an IF(ISNUMBER(SEARCH) statement. But I realise that if I were to do so for >1 category, I would have to start nesting per category if I were to continue to use IF(ISNUMBER(SEARCH) statements.

Is there a more scalable function suited to handling many categories?