How to create a relationship between Budget column and Calendar column

[RNGAKAM]

Hello,
I am a beginner on POWER BI.
I am integrating the budget into power bi, and I can not establish a relationship between the MONTH line in my budget column and the MONTH row in the CALENDAR column.

I receive the following message: you can not establish a relationship between these two columns because one of them contains unique values.
Please help me.

[v-chuncz-msft · Accepted solution]

@RNGAKAM,

You may take a look at Many-to-many relationships in Power BI Desktop (Preview).