how can i load array to the function via pointers and use them for calculations in that function

I am trying to make my code more professional by using pointers. I am using C . My goal is to use pointers as much as it is efficient . I have function which shifts filtered signal values. there are 4 filtering steps and each od them hold 3 values. filta ,filtb,filtc, filtd and there is new coming data which also needs to be shifted.

here is my working code . Very bulky indeed

float32_t*  FilterShift_inCapsulated( float32_t   xfilt1a_0,  float32_t  xfilt1a_1,  float32_t xfilt1a_2) 
{
    //values area loading normal way

    float32_t xfilt1a[3],shiftedvalues[15];
    float32_t*  shiftedvaluesP;

   xfilt1a[0]=  xfilt1a_0;  // i am sending them to arrays 
    xfilt1a[1]= xfilt1a_1;  //bc i want use them in "for" loop.
    xfilt1a[2]=xfilt1a_2;


int8_t ix = 0;
for (ix = 0; ix <2; ix ++)
{
    xfilt1a[ix] = xfilt1a[ix+1];   //index 1 of array shifts to 0
 }                                 //index 2 of array shifts to 1


    shiftedvalues[0]=xfilt1a[0];  //need to  take that values back
    shiftedvalues[1]=xfilt1a[1];   
    shiftedvalues[2]=xfilt1a[2];


    shiftedvaluesP=shiftedvalues // take the adress of the array and return it; 

return  shiftedvaluesP;
}

and here what i image to be correct way of it.

float32_t*  FilterShift_inCapsulatedwithPointer(float32_t*   xfilt1a) 
{
    //xfilt1a is an array . 

    float32_t filt1a[3],shiftedvalues[15];
    float32_t*  shiftedvaluesP;

 filt1a[0]= *xfilt1a;   // should i use itlike this   *(xfilt1a+1)  or like this *xfilt1a+1   
     filt1a[1]= *xfilt1a+1;
        filt1a[2]=*xfilt1a+2;


int8_t ix = 0;
for (ix = 0; ix <2; ix ++)
{
    filt1a[ix] = filt1a[ix+1];
// i want to avoid using real values here . can i use pointers here ?
//memcpy(destination, source, sizeof(source)); 
}


    shiftedvalues[0]=       filt1a[0];
    shiftedvalues[1]=   filt1a[1];
    shiftedvalues[2]=       filt1a[2];



    shiftedvaluesP=shiftedvalues ;

}