Using SoapUI Parameters in an XPath Statement

I am using a Datasource test step with a datasource type of XML. I am trying to select specific children nodes predicated on a,SoapUI parameter (${PreviousStep#Field1}). When I code the Row and Column XPaths, they look like:

Row = //Level1/Level2[Field1=${PreviousStep#Field1}]/Level3

Column = Field2

When this code is run, I receive an XPath syntax error.

Is there a way to get this coding structure to work? If not, is there a method that will allow me to select which set of nodes to process.

The input XML looks like:

Level1
Level 2[1]
Field1 = 1
Level3[1]
Field2 = 1
Level3[2]
Field2 = 2
Level3[3]
Field2 = 3
Level 2[2]
Field1 =2
Level3[1]
Field2 = 1
Level3[2]
Field2 = 4
Level 2[1]
Field1 = 3
Level3[1]
Field2 = 10
Level3[2]
Field2 = 11
Level3[3]
Field2 = 12
Level3[4]
Field2 = 13

Please let me know if this is confusing. I will try to be clear.

Thanks,
Bill Bachelder