# Hierarchical Navigation
**Navigation block that displays the current topic, its parent and children (if any).** %BR% This is intended to be included in other topics, for example in a side navigation bar ([[WebLeftBar]]).
_NOTE: The lookup for parent and children will increase the loading time of your pages._
## Usage
Two sections are defined:
- `all`
- `children`
### Displaying the Parent - Current - Children block
> %INCLUDE{"%SYSTEMWEB%.HierarchicalNavigation" section="all"}%
generates:
When included in [[WebLeftBar]] (using default Pattern skin) this is styled to:
### Displaying child topics
> *Child topics:*
> %INCLUDE{"%SYSTEMWEB%.HierarchicalNavigation" section="children"}%
generates:
**Child topics:**
When included in [[WebLeftBar]] (using default Pattern skin) this is styled to:
%STARTSECTION{name="all"}%
%SEARCH{
"parent"
type="query"
topic="%BASETOPIC%"
web="%BASEWEB%"
nonoise="on"
format="- [[$web.$parent][$parent]]
"
}%
- %BASETOPIC%
%INCLUDE{"%TOPIC%" section="childlist"}%
%ENDSECTION{name="all"}%
%STARTSECTION{name="children"}%
%INCLUDE{"%TOPIC%" section="childlist"}%
%ENDSECTION{name="children"}%%ENDSECTION{name="children"}%
%STARTSECTION{name="childlist"}%%SEARCH{
"parent.name='%BASETOPIC%'"
web="%BASEWEB%"
type="query"
nonoise="on"
format=" [[$web.$topic][$topic]]"
}%%ENDSECTION{name="childlist"}%