How to extract values from xml column in a table using SQL Server

XQuery methods .nodes() and .value() to the rescue.

You may need to adjust data types. I used a generic VARCHAR(20) across the board.

SQL

--DDL and sample data population, start
DECLARE @tbl TABLE (InsuranceEntity_ID INT IDENTITY PRIMARY KEY, EntityXML XML);
INSERT INTO @tbl (EntityXML) VALUES
(N'<insurance insurancepartnerid="CIGNA" sequencenumber="1"
           subscriberidnumber="1234567" groupname="Orthonet-CIGNA"
           groupnumber="7654321" copaydollaramount="1"/>');
--DDL and sample data population, end

SELECT InsuranceEntity_ID
    , c.value('@subscriberidnumber', 'VARCHAR(20)') AS subscriberidnumber
    , c.value('@groupnumber', 'VARCHAR(20)') AS groupnumber 
FROM @tbl
    CROSS APPLY EntityXML.nodes('/insurance') AS t(c);

Output

+--------------------+--------------------+-------------+
| InsuranceEntity_ID | subscriberidnumber | groupnumber |
+--------------------+--------------------+-------------+
|                  1 |            1234567 |     7654321 |
+--------------------+--------------------+-------------+