You can improve the search results by making use of the simple query language. Here is a list of supported query terms with some examples.

is:open, is:pendingOpen issues.
is:closed, is:doneIssues marked as done.
submitter:<who>Issues submitted by a person named who, e.g. submitter:ludo for all issues submitted by ludo. The filter matches both the email address and the name.
author:<who>Issues where a person named who has commented, e.g. author:rekado for all messages where rekado has commented. The filter matches both the email address and the name.
severity:<type>Issues that have been marked with the given severity, e.g. severity:serious for all issues that have been labelled as serious bugs. The following severities are recognized: critical, grave, serious, important, normal, minor, and wishlist.
tag:<type>Issues that have been tagged with the given tag, e.g. tag:easy for all easy issues that are suitable for newcomers. The following tags are recognized: patch, wontfix, moreinfo, unreproducible, fixed, notabug, pending, help, security, confirmed, and easy.
date:<start>..<end>Issues submitted within the provided range. start and end can be one of now, today, a date in the formats YYYY-MM-DD or YYYYMMDD, or an amount and a unit for a point in the past, such as 12d.. for 12 days ago. Supported units are: h (hours), d (days), w (weeks), m (months), and y (years).
mdate:<start>..<end>This is just like date except that it also includes comments.
msgid:<message id>Find issues containing a message with the given message id.