Thanks for reaching out on the forums, Lauren!
What will help (me, at least) is a bit more specific idea of the data you're trying to present. Could you post a workbook or mockup using Superstore? Even describing a use case with specifics would help. There may be a really simple way to get you on the right track!
Are you saying you want to end up with Sheet 3 filtered so that there are some rows with value=1 based on what's happening in Sheet 2, and also have some rows with value=0 based on what's happening in Sheet 1?
What do you want to do on Sheet 3 when there are conflicts caused by Sheets 1 and 2?
And how are you expecting to have the user modify both Sheet 1 AND Sheet 2 and then have it reflected in Sheet 3. (All three on one dashboard, for example?)
A sample workbook would be really helpful here so that we can all be talking about the same things, specific to the example.
Thanks a lot for the input. I do see how my question was too vague, as I cannot post my workbook publicly. I managed to get to the solution I wanted by filtering on a calculated field in the third sheet.