docs(TraceView): Add documentation for span filters as panel options (#98721)

Co-authored-by: Isabel Matwawana <76437239+imatwawana@users.noreply.github.com>
Co-authored-by: Isabel Matwawana <isabel.matwawana@grafana.com>

docs/sources/panels-visualizations/visualizations/traces/index.md

@@ -166,3 +166,17 @@ You should now see a list of matching traces in the table visualization. While s
 ## Panel options
 
 {{< docs/shared lookup="visualizations/panel-options.md" source="grafana" version="<GRAFANA_VERSION>" >}}
+
+## Span filters
+
+The **Span filters** options control the initial state of the span filters when the visualization loads, allowing you to customize your trace analysis view.
+
+- **Find in trace** - Set the initial value to focus on spans relevant to your query.
+- **Show matches only** - Toggle the switch on to display only spans that match the defined filter criteria. This helps simplify trace interpretation.
+- **Show critical path only** - Toggle the switch on to highlight only the spans in the critical path, which helps identify performance bottlenecks and their impact on overall latency.
+- **Service name** and **Service name operator** - Define a specific service or pattern to narrow analysis to spans related to particular services.
+- **Span name** and **Span name operator** - Filter spans by name or pattern to focus on specific span types or processes.
+- **Min duration** and **Max duration** - Set duration thresholds to exclude spans outside the desired time range.
+- **Tags** - Add one or more tags to further refine the filtering criteria so only relevant spans are displayed.
+
+The options support variable interpolation, where you can set the service name to a variable `$var` and the visualization will replace it with the value for the variable named `$var` in the span filters. This applies to the service name, span name, duration fields, and tags.