Create a line chart from a DataSet using DateTime Field and value (decimal)

I am using Crystal Reports Developer 14.0.

I have a dataset with multiple tables related to each other (-> = One to Many)

   Level 1 -> Level 2 -> Level 3 ->Level 4

The data I wish to chart is in table level 4.  Each record in this table contains a DateTime column and a Value (decimal) column (among others)

I have tried to no avail to create a Line Chart plotting value on the y Axis and DateTime on the x axis.  Seems simple enough but I am missing something.

I have each table in my DataSet set up as a Group (4 groups) and I insert a chart using "Insert Chart" in the Group 4 Footer (Level 4 table).  I cannot find where I would set the data points for the x and y axis.  I can chose the Level4.Value field and set the "for each record" but nowhere do I see where to add the date field.

Help