Instead of giving a quick filter for month, create a parameter with all month values. that will allow user to select a month on runtime.
Now use parameter to calculate the current and previous month in a calculated field.
Use this calculated field as a filter to load only current and previous month.
Pulkit's method is the best way of going about this.
If you need help creating this you can look at the file attached on the below thread
Or feel free to upload a sample workbook and one of us can help you achieve this
Filters restrict data - that is the intention of a filter
To work outside of filters, as has been suggested - parameters
I wrote about this kind of thing some time back
Really thank you for your replies, but I still didn't have the grasp of using parameter on Tableau for date control (I'm still learning using Tableau)
Here I have the workbook attached, with dummy data
Really thank you if you could give me some light on my problem
Example Workbook.twbx 23.5 KB