diff --git a/Source/Diagnostics/BTDiagnostics.cpp b/Source/Diagnostics/BTDiagnostics.cpp
index fb83f5a65e7..aba5cc14874 100644
--- a/Source/Diagnostics/BTDiagnostics.cpp
+++ b/Source/Diagnostics/BTDiagnostics.cpp
@@ -906,7 +906,6 @@ BTDiagnostics::DefineFieldBufferMultiFab (const int i_buffer, const int lev)
     auto & warpx = WarpX::GetInstance();
 
     const int hi_k_lab = m_buffer_k_index_hi[i_buffer][lev];
-    amrex::Print() << "hi_k_lab = " << hi_k_lab << "\n";
     m_buffer_box[i_buffer][lev].setSmall( m_moving_window_dir, hi_k_lab - m_buffer_size + 1);
     m_buffer_box[i_buffer][lev].setBig( m_moving_window_dir, hi_k_lab );
     amrex::BoxArray buffer_ba( m_buffer_box[i_buffer][lev] );
@@ -957,7 +956,6 @@ BTDiagnostics::DefineFieldBufferMultiFab (const int i_buffer, const int lev)
         // Refine the geometry object defined at the previous level, lev-1
         m_geom_output[i_buffer][lev] = amrex::refine( m_geom_output[i_buffer][lev-1],
                                                       WarpX::RefRatio(lev-1) );
-       //amrex::Print() << "DefineFieldBufferMultiFab lev == 1 : m_geom_output[i_buffer][lev] = " << m_geom_output[i_buffer][lev] << "\n";
     }
     m_field_buffer_multifab_defined[i_buffer] = 1;
     WARPX_ALWAYS_ASSERT_WITH_MESSAGE( m_mf_output[i_buffer][lev].boxArray().size() == 1,
diff --git a/Source/Diagnostics/ComputeDiagFunctors/BackTransformFunctor.cpp b/Source/Diagnostics/ComputeDiagFunctors/BackTransformFunctor.cpp
index f6f2bcd1205..874ad1ec0c6 100644
--- a/Source/Diagnostics/ComputeDiagFunctors/BackTransformFunctor.cpp
+++ b/Source/Diagnostics/ComputeDiagFunctors/BackTransformFunctor.cpp
@@ -60,6 +60,14 @@ BackTransformFunctor::operator ()(amrex::MultiFab& mf_dst, int /*dcomp*/, const
         const int scomp = 0;
         // Generate slice of the cell-centered multifab containing boosted-frame field-data
         // at current z-boost location for the ith buffer
+        // Create a 2D box for the slice in the boosted frame
+        const amrex::Real dx = geom.CellSize(moving_window_dir);
+        // index corresponding to z_boost location in the boost-frame
+        const int i_boost = static_cast<int> ( ( m_current_z_boost[i_buffer]
+                                            - geom.ProbLo(moving_window_dir) ) / dx );
+        amrex::Box box = warpx.boxArray(m_lev).minimalBox() ;
+        // Checking if the index of the slice is within the box of the boosted frame region at level, m_lev
+        if ( !( (i_boost > box.smallEnd(moving_window_dir) ) && (i_boost < box.bigEnd(moving_window_dir) ) ) ) return;
         slice = amrex::get_slice_data(moving_window_dir,
                                      m_current_z_boost[i_buffer],
                                      *m_mf_src,
@@ -70,12 +78,6 @@ BackTransformFunctor::operator ()(amrex::MultiFab& mf_dst, int /*dcomp*/, const
         // Perform in-place Lorentz-transform of all the fields stored in the slice.
         LorentzTransformZ( *slice, gamma_boost, beta_boost);
 
-        // Create a 2D box for the slice in the boosted frame
-        const amrex::Real dx = geom.CellSize(moving_window_dir);
-        // index corresponding to z_boost location in the boost-frame
-        const int i_boost = static_cast<int> ( ( m_current_z_boost[i_buffer]
-                                            - geom.ProbLo(moving_window_dir) ) / dx );
-        // z-Slice at i_boost with x,y indices same as buffer_box
         amrex::Box slice_box = m_buffer_box[i_buffer];
         slice_box.setSmall(moving_window_dir, i_boost);
         slice_box.setBig(moving_window_dir, i_boost);