lets assume you have two drop down lists (ddl) on your form one name field1 and one named field2 "how inventive :)"
double click your first ddl and select look up values in a dataconnection to a database.... select your secondary datasource from which you get the values of your database from the first drop down list, select the repeating node (under which your claimvalue and empids) are for the entries field and select empID as the value and display name.
for your second ddl repeat the steps described but select ClaimValue for dispaly name and value. click to the button next to the entries field and select filter data and click add. from the first drop down list of the filter select empID - "is equal to" - form the last drop down list select use formula and use this as your function current()/my:field1
If it works like expected your second ddl should now be populated only with values which fit your selection within the first ddl.
Hope this hepls.