Implement an Advanced Search
List the users who posted at least two items that are posted on the same day, one has a category of X and another has a category of Y.
In terms of user interface, you will implement two text fields, so that you can input one category into each text field and the search will return the user (or users) who (the same user) posted two different items on the same day, such that one item has a category in the first text field and the other has a category in the second text field.