So you should create two separate fields, one containing Products, and the other containing the broader range of variations (let me know if you need help creating this).
Then, what you want becomes trivial - you just have two separate filters, one for Products and one for Variations. Tableau has an option under Filters that allow you to only display a subset of the items that are relevant to the other filters. What you do is click on the arrow on the top of the filter and select "Only Relevant Values" near the bottom.
Thank you for the quick response! Yes, I would definitely like some help creating the fields.
I'm confused as to why you have them all in one column in the first place - shouldn't you have categories and then sub-categories?
In any case, I'll swing. If you have variations in the "Item 1 and Variation 2" format, you can split this field into two columns with this calc:
SPLIT([Field], 'and', 1)
SPLIT([Field], 'and', 2)
So you can all the first calc Product, and the second calc Variation. If it is in the "Item 1, Variation 2" format:
SPLIT([Field], ', ', 1)
SPLIT([Field], ', ', 2)
...etc. It seems like you will need to play around with such string manipulation calculations to get the result you want.