Hi,
Yes, as Marsha has suggested. .WaitElement() is a new method introduced in TC 14.40 for Cross-platform testing.
Note that test code created for cross-platform testing cannot use NameMapping/Aliasing, requires license for Device Cloud addon and applicable to page object only (which potentially means decreased performance).
Otherwise, you must implement your own wait mechanism to wait in a loop until the sought-for object appears or timeout occurs.
One more note as for your code.
The code looks like a port from Selenium code that implements page object model. This code in TestCOmplete will work only in the case if all sought for objects (viewcombtn, select_lst, ...) exist at the moment of search. If the select_lst object appears only after the click on the viewcombtn, then your code will not work because the search for select_lst will fail anyway as the object will not exist until the button is clicked.