Declare a global workbook time parameter before synchronizing chart brushing

Source facts

Microsoft says a global workbook parameter must be declared in a parameters step using the global option. Selections, brushing, links, buttons and tabs can update an existing global parameter, but cannot create one. The declaration determines whether those interactions can update a shared value. Microsoft Learn.

Applicability

Use this review for a workbook intended to synchronize time selection across multiple charts. Identify which controls should share the value and which should remain independent. Review the parameter dependencies before making an existing local parameter global.

DSE recommendation

DSE recommends declaring the shared parameter once and documenting which chart inputs and outputs use it. Test a copied workbook before changing the shared report. Keep unrelated filters local, and have a reviewer inspect dependencies for unintended cycles. Label the active time selection so readers can understand the scope of the displayed evidence.

Verification

Brush a time interval in each participating chart and confirm that all intended charts update, including those above the changed control. Verify that intentionally independent charts retain their own scope. Reload the workbook and repeat the interaction from its default state. Preserve the tested parameter declaration and bindings with the workbook version used for the report.

Official references

Microsoft Learn: Create workbook parameters.