a quick question , I've not been able to find an answer on the internet. I've 3 report tables on 1 Dataset , 2 of these reports are hidden and the only reason they exist is to display data on a chart.
The problem is that I can't create the chart using either one of these hidden tablix reports as a source , the chart is pulling the data from the first tablix report added to the Dataset which is not hidden.
I need to create a chart for each of the highlithed tablix report tables
This is not possible in SSRS that a tablix is your datasource for a chart. The datasource of your chart can only be a dataset. Also a tablix datasource can only be a dataset. Under Chart properties > Dataset name you will find only datasets in the drop down. You have to edit your query the way you need it for your chart.
You have this option in Power BI. There you can import your dataset in a table, edit this table as often as you want and use the end table as your chart datasource.