# Matrix Column and Reference Value
When referencing a sheet that contains Matrix Columns in its columns from other sheets using filters, you can reference not only regular column values but also child column values and series values of Matrix Columns. Series values in particular allow you to reference the start and end dates of series periods, making it possible to filter record displays on separately displayed sheets using the period of the series selected within the Matrix Column as a condition.
## Referencing Child Column Values
To reference child columns of a Matrix Column, select a sheet containing Matrix Columns as the reference target in the reference value selection dialog, choose the Matrix Column for the key column, and select the child column you want to reference from the submenu.
When referencing child column values, if the sheet cursor is inside the referenced Matrix Column, the reference value will be set to the child column value of the series where the cursor is located. If the cursor is outside the Matrix Column, no reference value will be set.
{% hint style="info" %}
When referencing child column values, the target range for key values is always limited to selected record values only.
{% endhint %}
## Referencing Series Values
To reference series values of a Matrix Column, similarly select (Series Value) from the submenu of the selected Matrix Column. Choose one of the following values to reference:
* **Series Period Start Date** - References the first date when the selected series is expressed as a period. For example, if the Matrix Column display interval is "monthly" and the cursor is on the "2023/4" series, this value would be "2023-04-01".
* **Series Period End Date** - References the last date when the selected series is expressed as a period. For example, if the Matrix Column display interval is "monthly" and the cursor is on the "2023/4" series, this value would be "2023-04-30".
When referencing series values, if the sheet cursor is inside the referenced Matrix Column, the reference value will be set to the start/end date of the period for the series where the cursor is located. If the cursor is outside the Matrix Column, the reference value will be set to the start/end date of the entire Matrix Column period.
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