If you use the "Combine with Similar Request"

method in OBIEE, for instance in the case of making a "DateTime" aware graph (
http://knowledge.ciber.nl/weblog/?p=93 or
http://obiee101.blogspot.com/2008/03/obiee-continues-time-line.html) you will loose the filterview.

This is caused because the filterview only looks at the outer query of the UNION ALL statement:

This logically leads to "Request contains no filters

I have developed a workaround for this problem:
Open a new request with a dummy column:

The CASE when 1=0 statement prevent executing from the query so it won't use any resources.
On this request put all your "prompt"columns in the filter and set them on "is prompted"or use "named prompts" {
} .
Be sure to also incoperate your "hard coded" filters!Add the filterview to your compound layout and remove all other views:

Save your request as "Filterview"

Add the request to your dashboard and now you have the content off your filter on your dashboard.

Till Next Time