What are they?
If you adjust the same parameters to analyze data in various optimizations, you can save them as custom filters. This will allow you to easily access them every time you access the optimization without the need to set them up again. You can create a filter just for yourself or for your entire team.
Creating a Filter
To create a filter, select the parameters you want to use, and click on the "Save Filter" button. You can choose to save the filter to be available only to you, or to share it with your team.
If you want to use the filter across campaigns, you can save it "For My Team". If the limit (lower/upper) is not highlighted, this means that the custom filter will update the limit depending on the account. E.g. if Campaign 1 has a maximum of 100 Impressions, and Campaign 2 has 2000, the custom filter will take the upper limits in both campaigns automatically.