This is what I want to do: Show data just from a Matrix row whose Playa column is the child that 2 channels (coparents) share.
I have 3 channels: Sizes, Colors, and Price Groups. Sizes has a playa field "cf_price_group_playa" which references Price Group, and Colors has a Matrix field, cf_size_price, with a playa column, that references the channel Price Group as well. I want to pull only the price for this size in the price group that the color I'm currently looking at is in; if I don't search explicitly on that playa column, I get all the matrix rows:
{exp:channel:entries channel="colors"}
{exp:playa:coparents channel="sizes" field="cf_price_group_playa"}
{cf_size_price search:price_group="THE_SHARED_PRICE_GROUP"}
{price}
{/cf_size_price}
{/exp:playa:coparents}
{/exp:channel:entries}
I'm clearly doing something wrong and am tripping myself up figuring it out. It seems so clear, the relationship among these channels, but I'm not getting the front-end bit right. I appreciate insight from the Playa gurus here!