Present key figure on text field filtered by hierarchy

Hello,

We are quite new to SAP BO Design Studio and struggling with the following:

There is a dropdown list on our canvas, populated with a hierarchy:

DROPDOWN_1.setItems(DS_1.getMemberList("0PROFIT_CTR", MemberPresentation.INTERNAL_KEY, MemberDisplay.TEXT, 20));

This works as expected. We can see the individual hierarchy nodes.

What we want to achieve now is that we want to display 1 specific key figure value (net sales) on a text component.

We think the onselect event for DROPDOWN_1 should look like this:

TEXT_1.setText(DS_1.getDataAsString("net sales",{"0PROFIT_CTR":DROPDOWN_1.getSelectedValue()}));

unfortunately this throws an error: Could not find member "example member" of dimension "0PROFIT_CTR" in getDataAsString("net sales", {"0PROFIT_CTR": "example member"}). It may have been filtered out.

If we try to manually pass the input value for 0PROFIT_CTR it works. The manual value we pass looks like this: HIERARCHY_NODE/0HIER_NODE/example member

Any suggestions?