Please improve this code,

FILTER MATCH_ACTIVITIES ( "finalResult_0_005"."ACTIVITY" , NODE '<%=display_code_1%>'] ) = 1;

so that when nothing is assigned to the display_code_1 value, it displays all the data.

I tried

FILTER CASE WHEN '<%=displayCode_1%>' IS NULL THEN 1 ELSE MATCH_ACTIVITIES("Correlation_0_0075_remove_1st"."ACTIVITY", NODEN'<%=displayCode_1%>']) END = 1 

this code but it did not worked.

It returns MATCH_ACTIVITIES: Could not find activity i]. this message. 

Thank you