First, add 2 (or 3) new number parameters to the “Check ins collection” and label them “Month” and “Year” (optionally add the 3rd for Day).
On the home screen, add 2 more input components and label them “Month” and “Year” (and the optional 3rd input for “Day”).
Make the inputs transparent and/or hide them behind a rectangle.
Set the default value for all 3 to “Date & Time > Current Time” and then change the date format to the specified format for each field. Month = Month Number, Year = Year Number, Day = Day Number.
On the “Create check-in action” add the 3 values from the 3 inputs into the check-in parameters so that Month has the month’s number, Day has the day number, and Year has the year number.
So on the user-facing side, if the counts are displayed on the home screen, simply filter the counts by the same inputs you used to create the check-in. If the user-facing side screen where the counts are displayed is on a different screen, add the 2 (and optional 3rd for Day) input fields from the previous step and use them as a filter.
The filter would be: Month > is equal to > Month Input and Year is equal to Year Input. The “Day” would be for you to use as a filter on an analytics page of some sort, hence why the Day is optional and not required for calculating “This Months” data.