I have implemeted the functionality using the following logic in designer!. This displays the logged in user requests where a column called "response" is NOTNULL. Response of type MultiLine Textbox.
** To Display a view with Multline NotNull Field and created by Current Logged User**
SelectCommand="<View><Query><Where><And><Eq><FieldRef Name="Author"/><Value Type="Integer"><UserID/></Value></Eq><IsNotNull><FieldRef Name="Response"/></IsNotNull><
** To Display a view with Multline Null Field and created by Current Logged User**
SelectCommand="<View><Query><Where><And><Eq><FieldRef Name="Author"/><Value Type="Integer"><UserID/></Value></Eq><IsNotNull><FieldRef Name="Response"/></IsNull><