This page contains ten nested instances of the {{P1}} template, written out indirectly using two nested instances of {{User:ais523/P1x5}} (which itself contains five nested instances of {{P1}}).
This is the argument to the innermost P1.
The "highest expansion depth" for this page is 23, higher than any of the other techniques. (Based on these results, it seems that a call to User:ais523/P1x5 adds an extra 7 to the expansion depth over and above the number of nested templates it expands to. Similar behaviour can be seen via adding a call to that template by itself on a page of its own; the resulting expansion depth is 12, even though the template's own expansion depth is 7.)