Replacing the MS-Acccess frontend for accessing linked tables with SQL Server?
SQL Server Management Studio allows you to create multiple versions of queries where you can see the SQL text and results simultaneously.

You can use dotted-notation to refer to tables in separate databases on the same server like:

SELECT * FROM database.schema.table


If you need to query data from multiple servers, you can create linked servers in SQL Server that provide all the capabilities of an Access front-end.  This allows you to use 4-part dotted-notation like:

SELECT * FROM server.database.schema.table


For example, this code creates 2 Databases on the local SQL Server, with 2 tables that contain a single record each.  The SELECT at the end joins data from the 2 tables into a single output:

CREATE DATABASE Test1 ON PRIMARY 
    (NAME = 'Test1_Data'
        , FILENAME = 'C:\Temp\Test1_data.mdf'
        , SIZE = 10MB
        , MAXSIZE = UNLIMITED
        , FILEGROWTH = 10MB
    )
LOG ON
    (NAME = 'Test1_Log'
        , FILENAME = 'C:\Temp\Test1_log.mdf'
        , SIZE = 10MB
        , MAXSIZE = UNLIMITED
        , FILEGROWTH = 10MB
);

CREATE DATABASE Test2 ON PRIMARY 
    (NAME = 'Test2_Data'
        , FILENAME = 'C:\Temp\Test2_data.mdf'
        , SIZE = 10MB
        , MAXSIZE = UNLIMITED
        , FILEGROWTH = 10MB
    )
LOG ON
    (NAME = 'Test2_Log'
        , FILENAME = 'C:\Temp\Test2_log.mdf'
        , SIZE = 10MB
        , MAXSIZE = UNLIMITED
        , FILEGROWTH = 10MB
);
GO

USE Test1;
GO
CREATE TABLE TestTable1
(
    ID INT NOT NULL PRIMARY KEY CONSTRAINT PK_TestTable1 IDENTITY(1,1)
    , TestText nvarchar(255)
);

INSERT INTO TestTable1 (TestText) VALUES ('This is table 1 in database 1');


USE Test2;
GO
CREATE TABLE TestTable2
(
    ID INT NOT NULL PRIMARY KEY CONSTRAINT PK_TestTable2 IDENTITY(1,1)
    , TestText nvarchar(255)
);

INSERT INTO TestTable2 (TestText) VALUES ('This is table 2 in database 2');


SELECT * FROM Test1.dbo.TestTable1
UNION ALL
SELECT * FROM Test2.dbo.TestTable2;


The output is:

ID  TestText
1   This is table 1 in database 1
1   This is table 2 in database 2