If you created a Prompted Link in OBIEE and there is a currency prompt, there is a problem with the generated URL.
Details of [prompted links can be found here], with the pattern being a set of fields defining a column or variable to be set. The usual pattern is along the lines of :
col1=foo,val1=bar,var2=bing,val2=bong
To set the filter / variable values being passed.
Eg: