In TestNG @BeforeGroups create test with only 1 parameter generated from @Factory(dataprovider)

I have a particular problem regarding TestNG and annotations

I have created a factory with dataprovider which has 3 values

And I want my testsuite.xml to run this code and create in @BeforeGroups all 3 instances from dataprovider(currently it creates only 1). Is it at least possible?

    public class FactroryClass {
    @factory(dataprovider =data)
     public Object[] createTest(String code) {
            return new Object[]{new TestClass(code)};
    }

public class TestClass{
    public TestClass(String code) {
        this.code = code;
    }

 @BeforeGroups(groups = "prepare-data", dependsOnGroups = "prepare--files")
public void setUp() throws Exception {
    testMethod1(String a){
    //some actions with a which is set from dataprovider}
}

@Test(dependsOnGroups = "execute")
    public void test() throws Exception {
    //actions to verify results in the end
    }
}


public class PrepareFile {

    @Test(groups = "prepare--files", invocationCount = 1)
    public void test() throws Exception {
        //we prepare files here
    }
}



public class Run {

    @Test(groups = "execute", dependsOnGroups = "prepare-data", invocationCount = 1, alwaysRun = true)
    public void test() throws Exception {
        //Run here
    }