using a context node in a for loop

[David Carlisle]

> Should the function below work?
no:-)

a function does not automatically pass the current context, 
. is undefined in a function body, so you can't use relative paths like
'@id and @db-ref

Built in functions can take an empty param list () and automatically work on
the current node, but user defined ones can not do that: you have to call
it as

local:display-user-groups(.)
                          ^

and define it as

declare function local:display-user-groups($here as element()) as
element()* {
...
then use $here/@id  $here/@db-ref

or give yourself a current node again by 
$here/
(for $user-group ....
in which case you can use {@id} as you have now.

(The same is true for xslt2 functions by the way)

David