Do you have a workbook to display what you have tried so far. There are several examples of market basket analysis in Tableau found throughout the site.
We also have this Think Data Thurday video - Think Data Thursday: Let’s talk about sets, baby! - YouTube and this post about Level Of Detail calculations where cohort analysis examples are provided - Top 15 LOD Expressions | Tableau Software
I hope these get you going. If you get stuck, please provide a Tableau .twbx workbook showing where you are stuck and what's been tried and we can jump into assist.
I suggest you to try using XLSTAT , you get a 30 day free trial . IN the machine learning dialog box, click on association analysis , a dialog box appears now select minimum number of antecedents(no. of products you want to find a relation in between) as 1 or 2 or 3 or 4