Is it possible to display 2 type of Units within a parameter?

There are a few different ways to do this, including formatting the numbers as strings, but I prefer the following method: https://www.flerlagetwins.com/2020/02/dynamically-control-formatting-using.html

You'd first change c. Measure Select for US subsectors:

CASE [p. Measure Select for US subsector]
 
WHEN "US Sales, value of shipments, or revenue" THEN [US Sales, value of shipments, or revenue]
WHEN "US Total cost of materials" THEN [US Total cost of materials]
WHEN "US Number of employees" THEN [US Number of employees]
WHEN "US Annual payroll" THEN [US Annual payroll]
WHEN "US Production workers annual wages" THEN [US Production workers annual wages]
WHEN "US Production workers for pay period including March 12" THEN [US Production workers for pay period including March 12]
END

Then create two more calcs:

Number - Millions

// Show number in millions when appropriate.
IF SUM([c. Measure Select for US subsectors])>=1000000 THEN
    SUM([c. Measure Select for US subsectors])
END

Number - Other

// Show number in thousands when less than a million
IF SUM([c. Measure Select for US subsectors])<1000000 THEN
    SUM([c. Measure Select for US subsectors])
END

The important thing to remember is that only one of these will ever have a value--the other will always be NULL.

Now drag these to the label card then edit the label so that they are side-by-side:

Now format the pill using separate formatting options. Millions will use this, for example:

See attached.