Looking for similar values and return separate tables / dates

I have a document in a format


date (year-month) | page url |number of pageviews
2017-10 | /mysite1 | 56

The data goes back 3 years.


What i want to achieve?

Is it possible in excel to look at statistics for visits in october (most current) and check, which of them

- were also visited in september
- were visited in september and in august
- were visited in september, august and july

and so on... so which one were continuously visited. And return them in a separate table? (1 table for each, visited only in oct and sept, separate for oct, sept and aug ...)

And the second task

Look at the urls from october and in a blank cell return the date (month) of last visit (counted from current date)

I need your help, please.

I cant upload the file here, so here is an exaple (link) https://ufile.io/htilx

Of course there are a lot more data, this is just how the structure looks like