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The elements are grouped by the data, the element works with.
An example of this grouping is filters working with the keywords Meta data field:
The Details panel for this filterthis row:
In this grouping, the two filters are a FreeText filter and an InList filter. The relationship between these two keywords filters is the same as with any other single filter, ie the logical grouping of filters has no impact on the search itself.
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Some filters and value fields may not cannot be edited or deleted. This is signified by the rows being greyed out:
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